Propeller



Dec. 28.1926 1,612,028

J. KINCAID ET AL PROPELLER.

Filed July 6, 1925 INVENTORS Jomv KINC ID 6: Jomv GOULD AT-roRNE Y5 iarrsu JOHN KINCAID AND JOHN GOULD, F VANCOUVER, BRITISH COLUMBIA, CANADA.

PROPELLER.

Application filed July 6, 1925. Serial No. 41,741.

Our invention relates to improvements in propellers the objects of which are to provide means whereby the power of the engine is effectively converted to propulsion energy, to prevent slip, to prevent the water which passes the propeller from diverging from the longitudinal axis of the propeller, to eliminate vibration on the ship to which the propeller is fitted, to improve the sh ps response to the helm and to eliminate cav1tation.

The invention consists essentially of a propeller having a plurality of blades set to a desired pitch from their entering edges to a point intermediate their width, the blades being curved along their leaving edges to produce an added thrust to the water displaced thereby and one or more segmental fins extending rearwardly of the blades, as will be more fully described in the following specification, in which Fig. 1 is a side view of the propeller as fitted to a ship.

Fig. 2 is a plan view of one of the blades.

Fig. 3 is a: view of a blade as seen from the line F-F of Fig. 2.

Fig. i is a sectional view of a blade taken on the line CO of Fig. 2.

Fig. 5 is a diagrammatic view showing the pitch and reaction curves.

Fig. 6 is a view of the propeller hub.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral 1 indicates the stern of a ship having a stern tube 2 and a rudder post 3 and a rudder 4:. The numeral 5 indicates generally a propeller formed as an integral casting or built up with separate units as shown, of which 6 is the hub, 7 the hub cap and 8 the blades. Each blade 8 is laid out to a predetermined pitch for a portion of its width as indicated in Figure 5 at A-A, BB, CC and DD, the pitch being constant from the entering edge 9 to a point somewhat to the rear of a medial line E of the blade, though this point may be varied according to the speed or other re quirements of the propeller. The leaving edge 10 of the blade on the rear or thrust side is curved as at 11 for the purpose of deflecting the water acted upon by the blade in a substantially direct axial line of the propeller shaft. The rotary action of the blades 8 produces a corresponding centrifugal action to the water against which it obtains its thrust, we therefore provide one or more segmental fins 12 concavo-convex in cross section and extending rearwards of the blade to prevent the water acted upon from slipping lengthwise of the blades and for directing it into axial alignment with the propeller shaft.

in some instances, such as on ships which are required tor towing purposes, and where great propeller eliiciency is desired when going astern we provide the leaving edge 10 of each blade with a fillet 18 which is curved in a reverse manner to the curve 11, so as to increase the efiiciency or the edge 10 when used in reversing, as an entering wedge.

In built up propellers in order that no undue disturbance shall be produced in the water meeting around the stern of the ship we provide the hub 6 with a plurality of tapering undercut bevelled slots 14: which are adapted to receive corresponding undercut bevelled lugs 15 which are provided on the inner end or heel of each blade. The lugs 15 are driven into the slots 14: of the hub and are held in place with an annular ring 16 bolted to the hub in any suitable manner.

Having thus described the several parts of our invention we will now briefly explain its functions.

The water after converging at the stern of the ship is acted upon by the propeller which on account of the curve 11 and the fins 12 is directed astern as a compact and substantially cylindrical column, thus producing a resistance to the propeller which results in greater speed to the ship per given propeller diameter, revolutions and pitch than in propellers in common use and also in the elimination of cavitation and the improvement in the steering of the ship to which it is fitted.

It will be obvious that a propeller of this description will be of value in aeroplanes and for other devices.

What we claim as our invention is:

A propeller comprising a hub and a plurality of radial blades the forward portion of the blades being set to a sequence of radially Varying angles forming a constant pitch throughout their length and being provided With a leaving portion curved in the direction of the propeller thrust, said curvature decreasing with the'increase of dis axis of the propeller.

Dated at Vancouver, B. (1., this 23rd day 1 of June, 1925.

JOHN KINCAID. JOHN GOULD. 

